锌碘电池中碘载体材料的研究进展

Research Progress on Iodine Host Materials for Zinc-Iodine Batteries

锌碘电池由于具有比容量高(211 mAh·g^(-1))、氧化还原电势理想(~0.54 V vs.H^(+)/H)、安全性高、锌和碘自然界储量丰富及价格低廉等特点而被广泛研究。然而,锌碘电池也存在一些缺陷,如碘及多碘离子导电性低、中间产物易溶于电解液、多碘离子转化反应速率缓慢及易发生穿梭效应等。目前,构筑碘正极载体材料是解决上述问题的常用有效策略。本文从设计理念、构筑方法、工作原理、电化学性能等方面综述近年锌碘电池中碘正极载体材料的研究进展,探究载体材料的组成、结构及形貌与锌碘电池电化学性能间的内在构效关系,揭示载体材料的物理限域与化学吸附/催化对电化学性能的协同增效机制。最后,结合碘载体材料当前存在的问题指明其未来可能的发展方向,如探索反应机理、催化中间产物转化、组装测试软包电池等。

Zinc-iodine(Zn-I_(2))batteries have been extensively explored,owing to the merits including high specific capacity(211 mAh•g-1),ideal redox potential(~0.54 V vs.H^(+)/H),high safety,reserve abundance in earth for zinc and iodine and low costs.However,Zn-I_(2)batteries also suffer from several drawbacks,such as low electrical conductivity of iodine and polyiodides,easy dissolution of intermediates in electrolyte,slow conversions of polyiodides and shuttle effect.Currently,the most efficient strategy for resolving these issues is constructing iodine hosts with unique structures.The recent progress on host materials of iodine cathode in Zn-I_(2)batteries was systematically reviewed from the aspects of design concept,constructing approaches,working principles and electrochemical performance,and the inside performance-structure relationships between the compositions,structure and morphology of iodine hosts and the electrochemical performance of Zn-I_(2)batteries was investigated,and the synergistic effects between the physical confinements and chemical adsorption/catalytic effect of host materials to the enhancement of electrochemical performance was revealed.Lastly,based on the remaining existed issues for iodine hosts,the possible development directions in the future were pointed out,such as exploring reaction mechanisms,promoting intermediate conversions,assemble and testing of soft-package batteries,and so on.